Apparatus for dialyzing



Nov. 19, 1946.- RE|HEL L 2,411,239

APPARATUS FOR DIALYZING Filed July 8, 1943 2 Sheets-Sheet l INVENTOR FRANK H. RE/CHEL 0110 an mug o. RUSSELL.

ATTORN E Y Nov. 19, 1946.

APPARATUS FOR DIALYZ ING Filed July 8, 1943 2 Sheets-Sheet 2 b h 1 P 7/0 I I I in l l v NTORS FR/M/K EEC/{EL and nRr/lu a RUSSELL ATTORNEY F. H. REICHEL ET AL 2,411,239

Patented Nov. 19, 19.46

AFPARATUS FOR DIALYZlNG Frank H. Reichel and I Fredericksburg, Va., assignors to Sylvania Industrial Corporation, corporation of Virginia Arthur 0. Russell,

Fredericksburg, van, 11'

Application July 8, 1943, Serial No. 493,919 6 Claims; (01. 210-85) The invention relates in general to dialysis,

and, in particular, to an apparatus for the separation of a soluble substance from its solution by dialysis, and to correlated improvements designed to enhance the structure and function and to extend the uses of such apparatus. It has been proposed to dialyze soluble materials from their aqueous solutions through hydrophilic membranes, such, for example, as sheets of regenerated cellulose,parchment paper, and

the like. However, dialyzers employing membranesin the form of flat sheets have certain inherent disadvantages. For example, the edges of the sheets must be maintained under pressure or firmly'sealed toavoid loss of liquidduring dialysis. To clean the apparatus or to replace a broken sheet it is generally necessary to completely dismantle the dialyzer. Further, to de-' crease breakage, the membranes must. be supported over their surfaces.

ing the dilution of the'solution being dialyzed. Thus, sheet dialyzers of prior design have generally been complicated in construction, difiicult to repair or to clean and capable of handling only small volumes of liquid.

Accordingly, it is a general object of the present invention to provide a dialyzer which will be capable of handling large volumes of liquid and which will operate rapidly.

It is a further general object to provide a dialyzing apparatus which is easy to construct and to clean and in which broken membranes may be replaced without completely dismantling the dialyzer.

A specific object is to provide an apparatus for means of retarding the dilution of the solution posed therein, means to pass the solution to be dialyzed into contact with one surface of the tube,

means to pass another liquid into contact withthe other surface of the tube, means to heat the solution being dialyzedv and/or the other liquid, and preferably means to maintain a pressure differential between the inside and-the outside of the tube to distend the tube.-

In the following specifications and in the appended claims, the term dialyzate will be used to designate the solution being dialyzed in ac- Finally, such prior apparatus did not provide any means for retard- .cordancewith recent usage in the art; the term diifusate will designate the solution oi-the material which diifuses through the-membrane during dialysis, and the term "dialysis will be used to designate the difiusion of soluble substances f through a semi-permeable membrane from one liquid into another.

The invention-accordingly comprises: the features of construction, combinations of elements, and arrangement of parts which will be exempli- .fied in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.

For a more complete understanding of the nature and objects of the invention, reference should be had to the accompanying drawingsv in which Figure 1 represents a sideelevation of one embodiment of the apparatus of the invention, and Figure 2 represents a cross-sectional view of the dialysis chamber of the apparatus of Figure 1 taken along the line 2-2 thereof. Figures 3 and 4 show two embodiments of means for anchoring the dialyzing tubes to the headers of the apparatus shown in Figure 1. I

In that embodiment of the apparatus shown in Figs. 1 and 2, the dialyzing chamber proper comprises a vertical outer chamber l0, which is shown as a cylindrical chamber, but which may be of any cross-sectional shape. The chamber is closed at the top by a plate II, and is closed at the bottom by a conical base' l2, which is provided with a drainl3 having a valve l4. Situated adjacent the ends inside the chamber Hi, there are positioned headers l5 and I 6, each provided with a plurality of holes into which are threaded short sections of pipe ll, which serve to anchor the dialysis tubes l8 to the headers.

The'chamber I0 is provided with a removable side portion 18 attached to the tank by the bolts 19 so as to make the dialysis tubes l8 accessible;

from the outside. When a tube bursts, it is thus possible to reach it and insert a new tube. To change a tube, particularly where it is in the center or opposite side of the chamber; it is desirableto drain the apparatus. The empty tubes obstructing the way may then be collapsed and pushed to one side to a. sufilcientextent to insert the new. tube in its proper location. In order toinsert a new tube'pit is' therefore not necessary, in general, to remove the tube located between the opening into the chamber and the tube to be replaced.

The anchoring or sealing of the dialysis tubes to the headers may be efl'ected by any suitable means, butthere is shown in Figs. 3 and 4 two or the like, which forms. a soft cushion to sup-' port the dialysis tube I8, which is slipped over the sleeve and fixed thereto by means of the cords 21. If desired, the outer surface of the sleeve I8 may be grooved to provide seats for the cord 2|. The lower end of the dialysis tube I8 may be united to the lower header by similar means as shown in Fig. 3. The joint shown in Fig. 3 is particularly advantageous when the chamber is being fitted with the tubes initially or when a dialysis tube is being replaced after breakage because, in this case, the disconnection of the lower section of the pipe I1 from the.

upper section, andthemounting of the tube I8 on the sleeve 28 can take place outside, of the chamber l8, after whichthe ends are joined to the headers by means of the threaded joint l9.

.An alternative means of anchoring the dialysis tubes to the headers is illustrated in Fig. 4, in which embodiment the header I5 is provided with a threaded section of pipe 22. is pulled through the section of the pipe and the end turned down over the upper end of the pipe 22 to form the cuff 23 which may be anchored to the pipe by means of the band 24, which may be formed of rubber as shown, or of metal or the like. The tube I8 may be mounted 'on the lower header I6 by means similar to that shown in Fig. 4. The coupling shown in Fig. 4 has the advantage of maintaining the maximum diameter of the tube I8 at the joint, and thus does not interfere with the flow of the liquid through the tube I8. I

The dialysis tubes I8 may be disposed and arranged withln the chamber |8 in any desired manner, in rows, for example, as shown in Fig. 2 or in concentric circles. The space between the tubes can be varied as desired, but in general a distance of the order of to 1 inch is sufficient. It is to be understood that a space exists around all of the tubes illustrated in Fig. 2, and

The casing 4 4 means of the heater 28 and introduced into the chamber I8 through the inlet 3|. The dialyzate fills the lower space 32 of the chamber, the tubes I8, and the upper space 33 until the level is such that the dialyzate overflows through the drain 34 which returns the excess to the evaporator 21. During operation, the dialyzate is preferably continuously circulated, Therefore, there' is I provided an outlet pipe 3.5 equipped with a valve "I4 which is positioned at the base of the conical bottom I2. and has'attached to its upper end an enlarged section 36 into which is disposed an extension tube 39 sliding through a hole provided in the packing 48. Between the ends of the tube 39, a branch 4| carries'the'solution into a pipe 42 which is attached to the upper end and surrounds the lower end of the pipe 4| which-slides therein. Pipe 42 discharges the dialyzate into the evaporator 21. By raising or lowering the pipe 39, it is possible to assure that the level of the dialyzate in the chamber 33 will be at all times above the header I5, and if necessary, up to the level of the overflow pipe 34. By this means, one can insure that the dialyzing tubes will be completely filled with the dialyzate even though the dialyzate is being circulated downward through these tubes.

i and I6.

The apparatus also includes means for bringing a liquid into contact. with the outside of the dialyzing tubes I8. These means comprise storage tanks 58 and 5| from which liquid may be removed by means of pipes 52, 53, and 54, each of which is provided with asuitable valve, the

downward and around the tubes I8 until it fills completely the space 59 between the headers I5 The excess liquid is removed from the lower'end of the space 59 through pipe 88, which has an enlarged upper end 38', an extension 39' that none of these tubes are in direct contact with. each other along their longitudinal surfaces. I

It may be understood that the apparatus shown in Fig. l may be constructed and arranged that the dialyzate may be caused to pass inside the tubes or outside the tubes, but for the pur pose of illustration only, the. apparatus of Fig.

' 1 is shown constructed so that the dialyzate will pass through the interior of the tube I8. The liquid to be dialyzed, that is, the dialyzate, may be taken from a suitable reservoir and fed through the pipe 25 having a valve 28 into an evaporator 21. The liquid in the evaporator may be heated from 30 to 100 0., preferably above 70 C., by conventional means and/or suction may be applied through the pump I8 to draw off water, alcohol and other volatile substances from the dialyzate. Heating and suction also facilitate elimination of bubbles from the dialyzate, the presence of which tends to favor the growth of organisms which attack the dialyzing membranes. The evaporator can be drained for cleaning by opening the outlet pipe -'II by means of valve 12. From the evaporator, the dialyzate passes through the pipe 29 by means of the pump 38, and is then heated by passing through the packing 48', the extension 39. having a branch 4| which discharges the liquid into a funnel 42 which is fixed into the upper end of the drain 8|. From pipe 6| the diffusate may be passed through the pipe 62 to the reservoir 5| or through the pipe 63 to the reservoir 58. The diffusate may be discharged from the reservoir 58 through the pipe 64 or from the reservoir 5| through the pipe 65 and forced by means of the pump 86 to storage or point of use.

While the apparatus shown in Fig. 1 is constructed so that both the dialyzate and the diffusate flow concurrently and downward. in the chamber I8, it 'is to be understood that the apparatus can be modified without transcending;

the scope of the present invention so as to provide that the dialyzate and the difiusate flow upward or fiow countercurrent to each other."

Further, the apparatus may be readily modified uid, the tubes willrequire little or no horizontal v support. If the tubes I8 are filled with dialyzate,

The pipe 35 is disposedvertically which has a higher specific gravity than the diffusate, the tubes will tend to float so that they can bekept in position merely by suitable guide pms. 1

During the process of dialysis, water from the diifusate continuously diffuses into the more concentratedgdialyzate, thus diluting the dialyzate and slowing down the process of dialysis. In order to avoid this decrease in the rate of diffusion resulting from dialysis, the present apparatus provides an evaporator 21 in which the dialyzate may be heated by means of the steam coil 28'. The

. top of the tank 21 is left open to permit 'evap ing both organic and-inorganic substances from organic or aqueous solutions. Organic substances may be separated from solutions by use of a semipermeable hydrophobic tubing. For the dialysis concentrate the dialyzate since water is evaporated in the evaporator; (b) to increase the rate of dialysis; (c) to eliminate dissolved air andair bubbles; (d) to sterilize the dialyzate and prevent further fermentation.

rate of dialysis from dropping too rapidly, thereby resultinginan increase in the yield.

Since certain changes may be made in the above construction and diiferent embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An apparatus for the dialysis of liquid solutions comprising, in combination, a chamber,

The apparatus has many advantages, namely,

' the dialyzing membranes being in the form' of a tube are more self-supporting than flat sheets and they can be readily anchored at each end without danger of leaks. When a tube breaks, the

liquid may be'quickl drained from the apparatus and a tube replaced without dismantling the entire apparatus. Since the 'tubes are not conmeans of dialysis comprising a dialyzing membrane in the form of a tube disposed therein, means for continuously circulating the solution to be dialyzed in contact with one surface of the tube, means for passing another liquid into contact with the other surface of the tube, means for concentrating the dialyzate after passage through the dialyzing tube, and means for recirculating the concentrated dialyzate through the tube.

2. An apparatus for the dialysis of liquid solutions comprising, in combination, a chamber,

concentrated dialyzate through the tube, and

means for maintaining a hydrostatic pressure differential between the inside and outside of said tube to distend the tube.

3. An apparatus for the dialysis of liquid solutions comprising, in combination, a, chamber, headers disposed transversely adjacent each end of said chamber so as to divide said chamber into a middle and two end compartments, a plurality of tubular dialyzing membranes disposed between said headers and communicating with the end compartments, means for continuously circulating a solution through the end compartments and through said dialyzing tub'esmeans for withdrawing said solution from said tubes, means for passing another liquid through said middle compartment into contact with the exterior of said dialyzing tubes and means for withdrawing said liquid I frontsaid compartment.

4. An apparatus according to claim 3 in which the tubes are affixed to the headers by means of a threaded union joint so that said tubes are separately removable.

5. An apparatus according to claim 3 in which there is provided means for concentrating one of said liquids positioned outside of said chamber.

6. An apparatus according to claim 3 in which there is provided means for heating at least one of said liquids.

FRANK H. REICHEL. ARTHUR O. RUSSELL. 

